If you use our Web statistics system to track visitors to your site, you'll see references to "hits", "pages viewed", "unique visitors", "authenticated visitors", "spiders" and "robots".
A hit is counted each time someone views a file (HTML file or graphic file) on your Web site. A single Web page can be made up of many files; for example, if your main Web page is one HTML file and ten image files, that would show as 11 hits when people view that page. If you're just interested in how many people are looking at your site, you probably don't care about hits.
Pages viewed is roughly the number of HTML pages or scripts that your visitors have viewed (a "page" is a "hit" that is not an image file and was not viewed by a "spider" or "robot").
Unique visitors is the approximate number of people who viewed pages on your site in a given month. Unique visitors are tracked by the IP address of the computer the person is using. If the same IP address returns to view your site within the month, that will add hits and pages, but won't increase the number of unique visitors. Note that the number of unique visitors is only a rough estimate: the IP address of some visitors could change between visits (depending on their type of network connection), and different visitors can sometimes appear to share the same IP address if they're behind a "proxy server" at a large company or ISP.
Authenticated visitors are people who visited a password protected directory on your Web site. If you don't have any password protected directories, you will have zero authenticated visitors.
Robots and Spiders are computers that examine the content of your Web site, rather than human viewers. For example, when Google examines your Web site to index the content, that will be shown as a robot or spider.
The countries shown by the statistics program are calculated by determining which ISP a visitor is using, then checking the country of that ISP.
All Web site statistics are slightly inaccurate.
Some visitors' IP addresses may change between visits, and some visitors go through "proxy servers" — computers at large ISPs such as AOL that can "cache" their own copy of your Web site files. For example, it's possible for two AOL users to view your Web site, but for AOL to show the second person a "cached" copy of what the first person saw, without connecting to your site again. That would show as a single visit in the statistics.
In addition, the listings of what IP addresses belong to which ISP, and which country that ISP is in, can sometimes be inaccurate.
Because of potential problems like this, your Web site statistics (like most statistics) should be considered useful information that's fairly accurate, but which might not be correct down to the last detail.